The Weight of Jupiter
by Oasis Blackmore
Summary: But the weight of Jupiter still was too much. The solar system collapsed. Post "Lies My Brother Told Me." Oneshot. Dasey.


**A/N: Yes, another post-eppy, Dasey, oneshot. I love 'em. This particular fic is post-"Lies My Brother Told Me." Once again, you should probably watch the episode before reading; it would definitely help the comprehension factor. Enjoy.**

The Weight of Jupiter

"The fact that Pluto's the smallest planet doesn't make it the first next to the sun, Derek!" Casey chided frantically, snatching the tiny planet from her stepbrother before he had a chance to eradicate Mercury's proper place in the solar system. "Just hold this side of the model, so Jupiter doesn't tip it over." She pointed at one side of the already wobbling project.

Derek grudgingly grabbed the structure, exhaling as he turned to view the flashing, digital clock on the microwave. "It's two in the morning," he complained.

Casey shot him a look, her tired hands working at fastening the large planet into place. The entire house groaned quietly as it relaxed, submitting to the night, and the world seemed to be hushed. The pair had unwillingly settled themselves in the kitchen, Casey fully intent on finishing the project as quickly and efficiently as possible, and Derek completely sick of this entire ordeal.

Derek watched Casey silently, his eyelids drooping. Her hair was every bit as tousled as it had been four days ago, when she had first attempted to cram this project into one evening's work. "Your hair looks great," he chuckled unenthusiastically.

Casey rolled her eyes, hooking Pluto at the end of the longest orbital of the piece. "I'm not in the mood for your lying right now, Derek." She took her hands away from the model, sighing in relief; it was almost complete. "It's what got us into this mess."

Derek looked at the solar system and stood up. "Okay, it's done. I'm going to bed." He let go of the side he had been holding, and Casey barely caught the as it made its way over the edge of the island.

"_Derek_!" she cried as he slouched through the doors and toward the stairs. "It's not finished!" Carefully letting the crooked display lay on the counter, she tiptoed after him, grabbing his wrist just as he set foot on the landing. "You aren't sleeping until it's done," she hissed furiously.

Derek turned to face her, countenance grim. "No, _you_ won't sleep until it's _perfect_. _I'm_ going to bed because our project _is_ finished."

Casey's eyes blazed. "You have to help me! You hardly did anything all night, anyway!" she snapped, tightening her hold on his wrist.

Derek glanced at her white-knuckled hand, raising an eyebrow. "Do you _really_ want to try this crap right now?" he asked, meeting her gaze as he shifted his arm so his hand easily enveloped her small wrist; their arms were now properly entangled. "Because I _will_ take you down."

Casey stared at him. "No, _I_ just want to finish this _stupid_ project," she replied, not yielding to his manipulative techniques. "And _you_ are going to _help_ me." She jerked him toward herself as she stepped in the direction of the kitchen, and he, being incapable of supporting his own weight due to lack of sleep, stumbled off the stair and directly into her.

They landed on the floor with a thump, and Casey winced at the pain she felt; Derek was on top. "Ugh! Get _off_ me, you _idiot_," she snarled, trying to push him away. "God, you're heavy."

"It's all muscle mass, baby," Derek bragged, taking his sweet time moving off her.

"Well, it's heavy, so get _off_!" She gave him a forceful, but futile shove, and he pushed himself up on his arms, hovering over her menacingly.

"That hurt," he berated.

Casey narrowed her eyes at him. "Yea, like you _falling_ on me didn't," she scoffed sarcastically. "Now, _move_." She tried to sit up, but his "muscle mass" stopped her. She glared into his eyes. "What? Do you want a 'Please'?" she growled.

Derek's eyes were now wide open, and his nostrils flared. "It would be nice, _Princess_."

"Well, it would be nice, _Derika_, if you would get off me before I _make_ you," Casey retorted.

Derek laughed. "Uh huh, _sure_. 'Cause I'm _totally _malleable."

"I'm shocked that you even know what that word _means_," Casey quipped darkly, taking this moment, when he seemed to be distracted, to go at him full force, and she managed to move him back a bit; but Derek re-pinned her to the ground.

"You _could_ just say please," he pointed out, sounding amused.

"Yea, but where's the fun in that?" Casey replied dryly.

Derek simply stared at her, looking expectant.

Her mind was racing, speeding, flying away, and she _hated _it. The thoughts that were running through her mind were unwarranted, unwanted. His lips did _not _look appealing or succulent or warm when they were pulled back into his trademark smirk; the twinkle in his laughing eyes was _not _adorable; and she was _not _inclined to move herself any closer to him. Where was her _control_? _He's my **stepbrother**!_

"One, little word," Derek taunted.

Casey's blood pressure was rising as she lie there, helpless, underneath her smirking stepbrother, and she was reaching her boiling point just as a confused voice drifted to her ears from the kitchen. "Casey?" It was her mother.

It was then that the teen girl realized just how bad their position would appear to an outsider; her cheeks went red, though no one could possibly see.

Luckily, the lord of the lies was on top of it, even though he was on top of her. "Casey tripped on the stairs," his voice rumbled through the darkness; she felt him moving away from her.

Nora's steps were hurried as she came into the room. "Is she all right?" There was a hint of accusation in her voice.

Derek must have caught it because his next words were laced with indignation. "Yes, she's all right. It's not like she's not used to falling down stairs." That stung.

"Casey, are you all right?" Nora asked softly, kneeling down and brushing a lock of tangled hair from her daughter's forehead.

"I'm fine, mom," Casey muttered, sitting up and seeing that Derek was inching his way up the stairs again. "_Derek _and I were just on our way up to get an extra pair of scissors," she lied, and Derek turned and raised his eyebrows at her.

"_Lying?_" he mouthed mockingly.

She rolled her eyes, getting to her feet.

Nora squinted at a clock nearby. "It's almost two thirty. You two are never going to wake up for school."

Casey smiled reassuringly. "We'll be fine." She looked up at Derek, who was reluctantly coming back down the stairs. "Come on, Derek. Let's _finish_ our project."

Nora smiled, always the trusting, accepting mother. She could never guess the thoughts that chased one another through Casey's brain at that moment. "Well, good night. Try not to stay up too late." She headed back into the kitchen and down to the basement bedroom.

Derek joined Casey at the bottom of the stairs, and she stuck her tongue out at him, happy to have defeated him. "Oh, that's _real_ mature," he taunted, following her into the kitchen. "Just tell me what we have to do to get this damn model done."

"Hold this." Casey again pointed at the side of the model that would fly up in the air in response to the weight of Jupiter, and Derek held it down with an exasperated sigh.

Carefully, Casey spun Saturn, the second largest planet in the solar system, so it was just opposite Jupiter, balancing the model perfectly.

"Let go," she said, moving her hand away from his.

He let go, and they both stared at the product of their painstaking efforts. A smile spread across Casey's lips as she looked up and met Derek's relieved gaze.

"_Finally_!" Derek cheered in a quiet tone, and if he had been prone to dancing, he certainly would have.

But Casey did all the dancing for him, joyfully cavorting around the island in her pajama bottoms, oversized T-shirt and fuzzy socks, despite her exhaustion.

Derek watched apprehensively.

She slipped; it had been inevitable, and Derek, in an unexpected act of heroism, caught her, supporting her back with his arm and swinging the other underneath her buckling knees, lifting her off the ground. "Klutzilla," he teased, sounding embarrassed or flustered or possibly even concerned.

"Idiot," she whispered, blushing uncontrollably.

"Grubby."

"Pig." With each insult, their faces drew closer,

"Prude."

"Womanizer." Until they were but centimeters apart.

"Casey." His voice was husky.

"Derek." His name came out as a moan as he pulled her closer.  
Their lips met, conductors of electric passion. Derek eased his arm from underneath Casey's legs, lowering her feet to the floor, and ran his fingers through her hair. She framed his face with her hands, slowly pulling away.

He looked bewildered, though a smile made itself known within seconds; he would never admit the impact she had on him.

She just stared, caught between ecstasy and disgust, love and hate, right and wrong, wrong and right. She _could_ never admit the impact he had on her.

There was something, and they were stepsiblings.

There was love, and they were supposed to hate one another.

But the weight of Jupiter still was too much. The solar system collapsed.

**A/N: Woot! This is a oneshot. Hope you enjoyed. Review if you like.**


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